Pendulum drawing device



Aug. 11, 1964 G. L. CHRISTIE PENDULUM DRAWING DEVICE 2 Sheets-Sheet 1 Filed April 2, 1962 INVENTOR GEORGE L. CHRISTIE MF ATTORNEYS Aug. 1 1, 1964 G. L. CHRISTIE PENDULUM DRAWING DEVICE 2 Sheets-Sheet 2 Filed April 2, 1962 INVENTOR GEORGE CHRISTIE B WW ATTORNEYS.

United States Patent 3,143,807 PENDULUM DRAWING DEVICE George L. Christie, 661 Island Park Drive, Ottawa 3, Ontario, Canada Filed Apr. 2, 1962, Ser. No. 184,437 7 Claims. (Cl. 33-27) This invention relates to a pendulum toy of the type disclosed in US. Patent No. 1,869,951 issued August 2, 1932 to G. E. Worthington and is directed in particular to improvements over the toy disclosed therein. The device disclosed in said patent is intended to produce various designs and comprises two pendulums mounted to swing relative to each other and connected together by means of two arms which overlie a table or support upon which paper is placed, said arms being connected together and provided with means for holding a pen, pencil or stylus.

The toy disclosed in the above-mentioned patent is rather cumbersome and is capable of producing only a limited range of designs. It also damps rather quickly and is subject to vibration of the writing instrument.

It is an object of the present invention to provide a toy which can produce a greater variety of designs than the toy disclosed in said US. Patent and which overcomes the disadvantages set out above.

As shown in the prior patent, the writing instrument is held by a split in one of two rigid arms which are adjustably connected together, the other arm being inserted through a slot in said one arm and held in adjusted position by suitable means. The ends of the arms remote from the writing instrument are connected with pendulums which, in swinging, cause the writing instrument to trace a design on paper positioned therebelow. Each of the rigid arms is alternately in tension and compression and must be of relatively large mass. Consequently, the weights on the pendulums must also be of relatively large mass.

According to the present invention, however, the writing instrument is carried by flexible members rather than rigid arms. Thus, in one embodiment of the invention, from each pendulum to the writing instrument there extend flexible connecting means, such as thin flexible wire, each such means preferably comprising two components diverging from the upper region of their associated pendulum and being connected to the writing instrument in the region of the upper and lower ends thereof. The flexible connecting means may comprise two separate lengths of material or a single length folded upon itself. At a point intermediate the connections of the said flexible components to the writing instrument I have connected tensioning means for applying a counterforce to maintain the flexible connecting means in tension, e.g. a further flexible element extending away from the pendulums and supporting a counterweight. This counterweight, by ensuring that the connection means between the pendulums and the writing instrument are always in tension, eliminates the need for rigid arms. The point of attachment of said further flexible element to the writing instrument is preferably adjustable whereby the contact pressure of the writing instrument on the paper may be adjusted at will. Moreover, the provision of the diverging flexible elements between each of the pendulums and the writing instrument eliminates or minimizes vibration of the latter, such vibration having been found to be a disadvantage of the prior art device as stated above. By using light flexible connection means instead of rigid arms, I can reduce the mass of the toy as a whole and of the weights used for the pendulums to a minimum.

The means for applying the countertorce may take the form of a suitably mounted spring or piece of elastic or the like, rather than the further flexible element and counterweight.

In one embodiment of my invention, I replace one of the pendulums with a pair of beat pendulums and thus I can achieve greater variety of design.

Embodiments of my invention will now be described, by way of example, with reference to the accompanying drawings, in which:

FIG. 1 is a perspective view of a first embodiment, utilizing two pendulums;

FIG. 2 is a perspective view of another embodiment, utilizing three pendulmus, two of which share common connection means with the writing instrument;

FIG. 3 is an enlarged perspective-view of a plastic ring used in either embodiment.

Referring first of all to FIG. 1 a board 1 has pendulums 2, 3 pivotally mounted thereon and connected by wires 4 with a writing instrument 5, a counterweight 6 also being connected to the instrument 5 by string 7 extending over a pulley 8. The pendulums 2, 3 and counterweight 6 control the movements of instrument 5 to create designs on a piece of paper placed under the instrument. Weights 9, 10 are mounted on pendulums, 2, 3 respectively, weight 9 being adjustable on pendulum 2 whereby the type of designs created by the instrument 5 in response to swinging movement of the pendulums can be varied.

It will be noted that each of the wires 4 extends from a plastic ring 11 at the top of the writing instrument to a hook 12 near the top of one of the pendulums, is twisted around this hook and extends from there to another plastic ring 13 at the bottom of instrument 5. It will also be noted that the string 7 is attached to a plastic ring 14 mounted on insrument 5 intermediate rings 11 and 13. Rings 11, 13 and 14 are all a sliding fit on post 15 which is part of instrument 5 and carries at its lower end an ink reservoir 16 and a nib 17. Moreover, as shown in FIG. 3, the rings have outer annular grooves 18 for retaining circular pieces of wire 19 provided with hooks or eyelets 20 for attachment of wires 4 and string 7 to the instrument 5.

The pulley 8 is mounted on an upstanding bracket 21 secured to board 1 and preferably provided with a guide plate 22 having a guide aperture 23 formed therein to receive string 7 and guide same. The pulley 8, of course, is grooved to retain string 7 thereon.

The board 1 is shaped in the form of a square with a projection at one corner thereof. The pendulums are mounted near two diagonally opposite corners and on adjacent sides of the board so that they swing at right angles to each other and the pulley is mounted at the end of the projections so that the string 7 extends from instrument 5 at about 45 to the wires 4. As result of this arrangement the toy may be placed on the corner of a table 24 with the centre of gravity of the toy disposed inwardly of the table corner so that no clamping of the toy to the table is necessary. This is another advantage of the present invention over the prior art. The variety of designs obtainable by use of the apparatus shown in FIG. 1 is clearly exemplified by the samples shown in FIG. 4.

The second embodiment, shown in FIG. 2 of the drawings, is similar to the embodiment just described, apart from the provision of two pendulums 25, 26 to replace the single pendulum 3. Pendulum 25 is similar to pendulum 3 but pendulum 26 differs in that provision is made for adjustment of the weight 27 thereon. The pendulums 25, 26 are interconnected by upper and lower cords 28, 29, respectively, which extend around upper and lower pulleys 30, 31 mounted in casings 32, 33, respectively. Casings 32, 33 are connected to the instru ment 5 by upper and lower hooks 34, 35 on the casings engaging in the hooks or eyelets 20 at the upper and lower ends of the instrument 5. The other parts of the toy shown in FIG. 2 are similar to the corresponding parts shown in FIG. .1 and need not be described again in detail. It willbe apparent that a greater variety of designs, as exemplified in FIG. 5, can be produced by this embodiment since two out of three of the pendulum weights are adjustably mounted on *their'pendulums and pendulums 25 and 2.6 can swing in or out of ph ase with oneanother and can have the same or ditferent amplitudes.

A spring 'or an elastic filament can be substituted for the cou nterweight 6.and string 7. The particular spring used may consist of 168 turns of chromel A wire of 0.016 diameter, tightly wound on a W mandrel. The elastic filament maybe 0.025" in diameter.

Although I have referred above to the device of the present invention being used as a toy, it will be apparent that it may be useful in other fields, for example in the fields of mental therapy, .education, design and decoration.

- 'What I claim as my invention. is:

1; In a toy for producing a variety of pleasing designs comprising a board, at least two pendulums adapted to be swingably mounted on said board with their upper ends disposed above the board, and controllable means adapted to be connected with said pendulums for control thereby, the. improvement comprising flexible connecting means to connect each of said pendulums with said controllable means, and tensioning means connectible with said controllable means, to apply a'counterforce thereto, the: arrangement being such that. each of said flexible connecting means is maintained in tension when the toy is opeach pendulum is connected to'the controllable means by 4? flexible means extending from both an upper and a lower region of the controllable means to a single connection with said pendulum, the tensioning means being connected to an intermediate region of the controllable means.

3. The improvement according to claim 2, wherein the connection of said tensioning means to the controllable means is vertically adjustable in said intermediate region.

4. The improvement according to claim 1, wherein three pendulums are provided, a pair of which share common flexible connection means to connect them with the controllable means, said common flexible connection means comprising in operative position upper and lower flexible members, each connected at its ends to the two pendulums of said pair, upper and lower rollers disposed between said pair of pendulums and said controllable means, 'said upper and lower flexible members extending around said upper and lower rollers, respectively, and

'means connecting said upper and lower rollers with the controllable means; t 5. The improvement according to claim 4, wherein the tensioning means is connected to the-controllable means between the connections of said upper and lower rollers to the controllable means. 7 V

6. The improvement according to claim'S, wherein the connection to the controllable means of said tensioning ReferencesCited in the file of this patent UNITED STATES PATENTS 

1. IN A TOY FOR PRODUCING A VARIETY OF PLEASING DESIGNS COMPRISING A BOARD, AT LEAST TWO PENDULUMS ADAPTED TO BE SWINGABLY MOUNTED ON SAID BOARD WITH THEIR UPPER ENDS DISPOSED ABOVE THE BOARD, AND CONTROLLABLE MEANS ADAPTED TO BE CONNECTED WITH SAID PENDULUMS FOR CONTROL THEREBY, THE IMPROVEMENT COMPRISING FLEXIBLE CONNECTING MEANS TO CONNECT EACH OF SAID PENDULUMS WITH SAID CONTROLLABLE MEANS, AND TENSIONING MEANS CONNECTIBLE WITH SAID CONTROLLABLE MEANS, TO APPLY A COUNTERFORCE THERETO, THE ARRANGEMENT BEING SUCH THAT EACH OF SAID FLEXIBLE CONNECT- 